It's an interesting one. Part of what makes Ascension what it is for me is just how wonky the cast list is.
On the original, neither trumpeter is right at all, the rhythm section is one step away from downing tools (except for when Hubbard plays, when suddenly they're all nicey nicey), and some of the saxophone players were really just randoms at the time, like Marion Brown. There are gaping holes like no Don Cherry and no Gato Barbieri.
I would like to discover that the new CryptoAscension had Hannibal Marvin Peterson and Alan Shorter on trumpet, or at least Ted Curson or Barbara Donald. I think that the failure to include stronger free trumpet is probably for me the weakest part of the original Ascension, both in terms of music and legacy - given what a star making record it was for the saxophone players, the lack of decent free trumpet effectively buries the instrument in the free context, leaving Don Cherry as the only high profile avant trumpet player until Lester Bowie. Cryptoscension is our chance to fix that, and get names like Alan Shorter stuffing the "spiritual jazz" sections of thousands of RSD sale bins.
For piano and drums, it would just be players who could keep up and were willing to be noisey (e.g. Burrell and Murray?) but perhaps Bobby Few on keys, if you were willing to make the new CryptoAscension into something quite different. I really like Few in a free blowing context.
For saxophone, Frank Wright would be a contender, to represent the Ayler crowd, and then Sam Rivers, doing something very different.